This invention relates to saxony carpet having improved appearance retention characteristics.
Two-ply nylon yarns and to a much lesser extent two-ply polyester yarns are used in the construction of saxony carpets. The yarns consist of crimped fibers and are used in the form of either continuous nylon filaments or nylon or polyester staple fibers. Conventionally, sufficient ply-twist is inserted in the yarns to provide optimum aesthetics in the carpet. The plied yarns are first treated (heatset) with either wet steam or dry heat at a temperature and for a period of time sufficient to set the twist and crimp in the yarn. The heatset yarns are subsequently tufted into a primary backing to form loops that are then cut to form individual short lengths (3/8 to 2 inches) (0.95 to 5.08 cm) plied yarn (hereinafter referred to as tufts). Each tuft is attached to and projects upwardly from the primary backing and terminates as a cut end. The carpet is then hot-wet dyed to a desired color in a conventional manner. The underside of the primary backing is then coated with an adhesive composition. The adhesive anchors the tufts in the primary backing and is applied to the backing in the form of a latex compounded emulsion which is then dried with heat to cure the adhesive. In most instances, a secondary backing is applied to the underside of the primary backing before the adhesive is dried and cured. Acrylic fibers are not commercially used in the construction of saxony carpets since during the hot-wet dyeing operations conventionally used acrylic fibers lose their crimp (i.e. they "lean out") and their ability to stand erect (i.e. they lean over and mat down).
Saxony carpet has a very pleasing initial appearance. The crimp in the individual fibers imparts exceptional cover and loftiness (i.e. firmness, resilience, and body) to the carpet while the ply-twist in the individual tufts gives the carpet a uniform and crisp appearance (i.e. tuft endpoint definition). Unfortunately, most, saxony carpet made from conventional carpet fibers lacks good appearance retention characteristics because the individual tufts of the carpet lose ply-twist when the carpet is subjected to normal traffic. This loss of ply-twist causes tuft ends to open up or "bloom", lose tuft endpoint definition and become entangled with neighboring tuft ends which gives the pile a matted appearance and causes the pile to develop "walkout" in traffic areas. The term "appearance retention" is used to describe the ability of carpet to retain its initial appearance with respect to tuft endpoint definition and lack of matting after being subjected to repeated traffics, where each "traffic" is the occurrence of an individual walking across the carpet.
Efforts in the past to improve the appearance retention characteristics of saxony carpet have not proven entirely satisfactory. For example, while appearance retention can be improved somewhat by inserting more ply-twist in the tufts, doing so also reduces the body of the carpet and provides a carpet having a lean look and a harsh hand, trade-offs the carpet industry is not willing to make and consumers are not willing to accept.
It is apparent, therefore, that saxony carpets having improved appearance retention characteristics and a pleasing appearance and hand would constitute a major contribution to the art.